Tiny gears on computer chips generate a vortex of light that could boost optical computing
For the first time, researchers have used tiny gears made of germanium to generate a vortex of twisted light that turns around its axis of travel much like a corkscrew. Because germanium is compatible with the silicon used to make computer chips, the new light source could be used to boost the amount of data that can be transmitted with chip-based optical computing and communication.
The researchers, from the University of Southampton in the U.K., and University of Tokyo, Toyohashi University of Technology and Hitachi Ltd., all in Japan, describe the new light-emitting gears in The Optical Society (OSA) journal Optics Express. With a radius of one micron or less, 250,000 of the gears could be packed into just one square millimeter of a computer chip.
There is a great deal of interest in generating light that is twisted, or has orbital angular momentum, because of its advantages for communications and computing. Today, light is used to carry information by varying the number of photons emitted or switching between light’s two polarization states. With twisted light, each twist can represent a different value or letter, allowing the encoding of a great deal more information using less light.
“Our new microgears hold the potential for a laser that can be integrated on a silicon substrate— the last component needed to create an integrated optical circuit on a computer,” said the paper’s first author Abdelrahman Al-Attili, from the University of Southampton. “These tiny optical-based circuits use twisted light to transmit large amounts of data.”
Using strain to improve light emission
It has been impossible to make a usable miniaturized light source on silicon, the material commonly used to make computer chips and associated components, because the material’s properties led to poor light-generating efficiency. Although germanium has similar limitations, applying strain by stretching it can improve its light emission efficiency.
“Previously, the strain that could be applied to germanium was not large enough to efficiently create light without degrading the material,” said Al-Attili. “Our new microgear design helps overcome this challenge.”
The new design features microgears that are freestanding at the edges so that they can be stretched by an oxide film deposited over the structures. This allows tensile strain to be applied without breaking the germanium’s crystal structure. The gears stand on a silicon pedestal that connects it to the top of the silicon substrate and allows heat to dissipate during operation.
To demonstrate their new design, the researchers used electron beam lithography to fabricate the very fine physical features that form the gears’ teeth. They then illuminated the gears with a standard green laser that did not emit twisted light. After the microgear absorbed the green light it generates its own photons that are circulated around the edges forming twisted light that is reflected vertically out of the gear by the periodic teeth.
Precision optical simulations
The researchers tested and tweaked their design using computer simulations that model the way light propagates in the gears over nanoseconds or even shorter time periods. By comparing the prototype’s light emission with computer simulation results, they were able to confirm that the gears generated twisted light.
“We can precisely design our device to control the number of rotations per propagation wavelength and the wavelength of the emitted light,” said Al-Attili.
The researchers are now working to further improve the efficiency of light emission from the germanium microgears. If successful, this technology would make it possible to integrate thousands of lasers onto a silicon chip for transmitting information.
“Silicon fabrication technologies that were developed to make electronic devices can now be applied to make various optical devices,” said Al-Attili. “Our microgears are just one example of how these capabilities can be used to make nano- and microscale devices.”
The Latest on: Optical computing
via Google News
The Latest on: Optical computing
- Scientists develop electro-optical device for faster computingon November 30, 2019 at 7:55 am
Scientists of Harish Bhaskaran’s Advanced Nanoscale Engineering research group at the University of Oxford has developed an electro-optical device that provides solution to faster and more ...
- Electro-optical device for faster computing developedon November 30, 2019 at 3:28 am
A first-of-a-kind electro-optical device that provides solution to faster and more energy-efficient computing memories and processors has been developed by scientists in Harish Bhaskaran's Advanced ...
- New electro-optical device may lead to faster processors: Studyon November 30, 2019 at 12:29 am
London, Nov 30 (PTI) Researchers have created a novel device which bridges the fields of optical and electronic computing, an advance that may lead to faster and more energy efficient memories and ...
- Computation at the speed of light achieved, new device bridges big gapon November 29, 2019 at 10:34 pm
Harish Bhaskaran's Advanced Nanoscale Engineering research group at the University of Oxford, partnered with other research universities, has conceived the first-of-a-kind electro-optical device. This ...
- Electro-optical device provides solution to faster computing processors: Studyon November 29, 2019 at 9:50 pm
Washington D.C. [USA], Nov 30 (ANI): In order to build the bridge between the optical and electronic computing, researchers have designed a first of its kind electro-optical device, which will help in ...
- Faster Computer Processors and Memory With New Electro-Optical Deviceon November 29, 2019 at 5:38 pm
First-of-a-kind electro-optical device provides solution to faster and more energy efficient computing memories and processors. In collaboration with researchers at the universities of Münster and ...
- Electro-optical device provides solution to faster computing memories and processorson November 29, 2019 at 11:03 am
scientists have created a first-of-a-kind electro-optical device which bridges the fields of optical and electronic computing. This provides an elegant solution to achieving faster and more energy ...
- Etisalat and Huawei Complete Industry's First Trial of ‘Compact Optical Cross-Connect’on November 27, 2019 at 1:11 am
and ultra-broadband all-optical transmission ON2.0 solution, helping Etisalat to achieve business success." With the emergence of new technologies and services such as cloud computing, big data, ...
- Interdisciplinary Team at UT Austin Envisions New Neuromorphic Computing Architectureon November 26, 2019 at 7:16 am
Alternative paradigms — some new, some old — are getting a fresh look from researchers. Neuromorphic computing is one such paradigm, as is optical computing where light takes the place of electrons as ...
- Powering future optical microsystems with chip-scale integrated photonicson November 25, 2019 at 4:45 am
To address the obstacles impeding the development of optical microsystems, DARPA developed the Lasers for Universal Microscale ... to navigation and timing, to quantum sensing and computing. To ...
via Bing News